[llvm] 91d4c0d - Reapply "[VPlan] Compute cost of scalar (U|S)Div, (U|S)Rem in computeCost (NFCI)."

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2025-09-14T13:15:07+01:00
New Revision: 91d4c0dfdf226665c17d4a44e2fab466e6103d18

URL: https://github.com/llvm/llvm-project/commit/91d4c0dfdf226665c17d4a44e2fab466e6103d18
DIFF: https://github.com/llvm/llvm-project/commit/91d4c0dfdf226665c17d4a44e2fab466e6103d18.diff

LOG: Reapply "[VPlan] Compute cost of scalar (U|S)Div, (U|S)Rem in computeCost (NFCI)."

This reverts commit 9490d58fa92bb338db96af331194c9ba26eb0201.

Recommits de7e3a58952 with a fix for an unhandled case, causing crashes
in some configs.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
index c6273074778d1..b72088bf1431e 100644
--- a/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp
@@ -3154,6 +3154,19 @@ InstructionCost VPReplicateRecipe::computeCost(ElementCount VF,
     return *getCostForRecipeWithOpcode(getOpcode(), ElementCount::getFixed(1),
                                        Ctx) *
            (isSingleScalar() ? 1 : VF.getFixedValue());
+  case Instruction::SDiv:
+  case Instruction::UDiv:
+  case Instruction::SRem:
+  case Instruction::URem: {
+    InstructionCost ScalarCost = *getCostForRecipeWithOpcode(
+        getOpcode(), ElementCount::getFixed(1), Ctx);
+    if (isSingleScalar())
+      return ScalarCost;
+
+    return ScalarCost * VF.getFixedValue() +
+           Ctx.getScalarizationOverhead(Ctx.Types.inferScalarType(this),
+                                        to_vector(operands()), VF);
+  }
   case Instruction::Load:
   case Instruction::Store: {
     if (isSingleScalar()) {